I have 2 Spyder Special Editions. One works fine and the other doesn't. It would discharge air once and then would have to be re-cocked. I turned the valve around and now it'll discharge air with each trigger pull. The problem now is the balls merely roll out of the barrel.

I cannot see any indication of what could be the trouble and it is the same air canister I used on both guns. Sounds like it fires but nothing.

Any ideas? Should I interchange parts from the one to see what happens?